Robot cleaner

ABSTRACT

By improving a structure of a discharge flow path of a robot cleaner, it may be possible to minimize a loss of a suction force, thereby reducing a noise without deteriorating cleaning efficiency. The robot cleaner includes a fan motor configured to generate a suction force, a first housing in which the fan motor is accommodated, a second housing in which the first housing is accommodated, and a chamber positioned between the first housing and the second housing, wherein a plurality of slits are formed in the chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application which claims thebenefit under 35 U.S.C. § 371 of International Patent Application No.PCT/KR2017/005280 filed on May 22, 2017, which claims foreign prioritybenefit under 35 U.S.C. § 119 of Korean Patent Application No.10-2016-0072122 filed Jun. 10, 2016 in the Korean Intellectual PropertyOffice, the contents of both of which are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to a robot cleaner capable of reducing anoise.

BACKGROUND ART

A robot cleaner is equipment that performs cleaning by autonomouslytraveling on an area to be cleaned without a user's operation andsucking foreign substances such as dust from the floor. During cleaning,the robot cleaner determines a distance to an obstacle, e.g., furniture,office appliances, walls, etc., present in the cleaning area through adistance sensor, and changes its driving direction based on thedetermined distance to clean the cleaning area.

The robot cleaner includes a main body with a fan motor and wheels fordriving the main body. In the bottom of the main body, a suction portionis provided to suck dust on the floor by a suction force of the fanmotor. The sucked dust is collected in a dust collector installed in theinside of the main body. In the suction portion, a brush for picking upforeign substances on the floor is installed. The brush is rotatablyinstalled on the bottom of the main body.

The inside space of the robot cleaner is small compared to that of acanister type cleaner or a upright type cleaner, and therefore, asmall-volume fan motor is installed in the robot cleaner. Thesmall-volume fan motor provides a weaker suction force than a fan motorinstalled in the canister type cleaner or the upright type cleaner.However, when the suction force of a fan motor is weak, cleaningefficiency may deteriorate.

A user can operate the robot cleaner to clean the floor, while doinganother activity in the same space as the robot cleaner. At this time,if the robot cleaner makes a loud noise, the user may find ituncomfortable to do the activity.

Since a greater suction force of a fan motor generally makes a loudernoise, fan motors having a smaller suction force and a smaller volume,compared to those installed in canister type cleaners or upright typecleaners, are installed in typical robot cleaners.

DISCLOSURE Technical Problem

The present disclosure is directed to providing a robot cleaner capableof reducing a noise by improving a structure of a discharge flow path.

Further, the present disclosure is directed to providing a robot cleanercapable of preventing deterioration of cleaning efficiency through anoise-reducing structure.

Technical Solution

One aspect of the present disclosure provides a robot cleaner including:a fan motor configured to generate a suction force; a first housing inwhich the fan motor is accommodated; a second housing in which the firsthousing is accommodated; and a chamber positioned between the firsthousing and the second housing, wherein a plurality of slits are formedin the chamber.

In a side of the first housing, an inlet opening through which airpassed through the fan motor enters the inside of the first housing maybe formed, and in another side of the first housing, an outlet openingthrough which the air entered the inside of the first housing isdischarged may be formed.

In a side of the second housing, an outlet hole may be formed, and airentered between the first housing and the second housing through theoutlet opening formed in the first housing may be discharged through theoutlet hole formed in the second housing.

At least two of the chambers may be provided, and the air enteredbetween the first housing and the second housing may pass betweenchambers adjacent to each other among the at least two chambers.

The plurality of slits formed in the chambers may be formed in onesurface of the chamber opposite to one surface of a chamber adjacent tothe chamber.

A plurality of the chambers may be provided to left and right sides ofthe outlet opening formed in the first housing.

The chamber may be formed by an outer side surface of the first housing,a rib protruding from the outer side surface of the first housing, andan inner side surface of the second housing.

The chamber may include a partition wall partitioning an inside space ofthe chamber.

A sound-absorbing material may be installed in an inside space of thechamber.

When a plurality of the chambers are provided, a sound-absorbingmaterial may be installed in at least one chamber of the plurality ofchambers.

An inside space of the chamber may be partitioned to a plurality ofspaces by a partition wall, and a sound-absorbing material may beinstalled in at least one space of the plurality of spaces.

An inlet opening may be formed in a lower portion of the first housing,and an outlet opening may be formed in an upper portion of the firsthousing.

Two chambers may be positioned below the outlet opening in such a way tobe spaced from each other, and air discharged through the outlet openingmay pass between the two chambers.

The second housing may include an inner housing in which the firsthousing is accommodated, and an outer housing surrounding at least oneportion of the inner housing.

The chamber may be positioned between the first housing and the innerhousing.

Another aspect of the present disclosure provides a robot cleanerincluding: a case forming an outer appearance; and a fan motor unitaccommodated in the case, wherein the fan motor unit comprises: a fanmotor configured to generate a suction force; a first housing in whichan inlet opening and an outlet opening are formed and in which the fanmotor is accommodated; a second housing in which the first housing isaccommodated and in which an outlet hole is formed; and a plurality ofchambers positioned between an outer side surface of the first housingand an inner side surface of the second housing, wherein a plurality ofslits are formed in the chambers, wherein the plurality of chambers arepositioned below the outlet opening in such a way to be spaced from eachother in both sides of the outlet opening so that air discharged throughthe outlet opening of the first housing passes through a space formedbetween facing chambers of the chambers.

A plurality of slits formed in any one chamber may be located in aportion of the chamber, which is adjacent to another adjacent chamber.

A sound-absorbing material may be installed in at least one chamber ofthe plurality of chambers.

An inside space of the at least one chamber of the plurality of chambersmay be partitioned by a partition wall.

The plurality of chambers may be formed by a rib protruding from anouter side surface of the first housing, the outer side surface of thefirst housing, and an inner side surface of the second housing.

Advantageous Effects

A robot cleaner according to an embodiment of the present disclosure canimprove cleaning efficiency and reduce the generation of noise.

Also, the robot cleaner can prevent a suction force of a fan motor fromdeteriorating.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a robot cleaner according to anembodiment.

FIG. 2 is an exploded perspective view of a robot cleaner according toan embodiment.

FIG. 3 is a perspective view of a fan motor unit according to anembodiment.

FIG. 4 is an exploded perspective view of a fan motor unit according toan embodiment.

FIG. 5 shows flow of air in a fan motor unit according to an embodiment.

FIG. 6 shows a part of a discharge flow path of a fan motor unitaccording to an embodiment.

FIGS. 7 and 8 show first housings according to other embodiments.

FIG. 9 shows a first housing according to another embodiment.

FIG. 10 shows a first housing according to another embodiment.

FIG. 11 shows a state in which sound-absorbing materials are installedin chambers according to another embodiment.

FIG. 12 is a perspective view of a robot cleaner according to anotherembodiment.

FIG. 13 shows a state in which air flows in a fan motor unit accordingto another embodiment.

MODES OF THE INVENTION

Hereinafter, a robot cleaner according to an embodiment will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a robot cleaner according to anembodiment, and FIG. 2 is an exploded perspective view of a robotcleaner according to an embodiment.

Referring to FIGS. 1 and 2, a robot cleaner 1 according to an embodimentmay include cases 2 and 3 forming an outer appearance, a fan motor unit6 for generating a suction force, and wheels 4 for driving the robotcleaner 1. Also, a brush unit 5 may be installed at one side of therobot cleaner 1. The brush unit 5 may be rotatably configured to pick upforeign materials on the floor. The robot cleaner 1 may further includea dust collector (not shown) for filtering out foreign materialsincluded in inhaled air to collect the foreign materials.

The cases 2 and 3 may include a lower case 2 in which the fan motor unit6, etc. are accommodated, and a upper case 3 covering the lower case 3from above. At one side of the lower case 2, an inlet 21 may beprovided. The inlet 21 may be formed in a front bottom of the lower case2. In the upper case 3, an outlet 31 may be formed through which inhaledair is discharged. The outlet 31 may be formed in a rear side portion ofthe upper case 3.

Two wheels 4 may be provided around left and right edges of the lowercase 2 in such a way to be symmetrical to each other. The wheels 4 mayenable the robot cleaner 1 to move forward/backward or rotate.

The brush unit 5 may be positioned in the inlet 21. The brush unit 5 mayinclude a roller rotatably installed in the inlet 21 and a brushsurrounding an outer circumferential surface of the roller. The brushunit 5 may rotate to sweep foreign materials on the floor toward theinlet 21.

The fan motor unit 6 may be positioned in the lower case 2. The fanmotor unit 6 may be connected to the inlet 21 through a flow path. Adust collector may be positioned between the fan motor unit 6 and theinlet 21 so that foreign materials included in air entered through theinlet 21 are collected in the dust collector, and clean air from whichthe foreign materials have been filtered out are discharged toward thefan motor unit 6. The clean air may pass through the fan motor unit 6and then be discharged to the outside through the outlet 31 formed inthe upper case 3.

FIG. 3 is a perspective view of a fan motor unit according to anembodiment, and FIG. 4 is an exploded perspective view of a fan motorunit according to an embodiment.

Referring to FIGS. 3 and 4, the fan motor unit 6 according to anembodiment may include a fan motor 60 for generating a suction force, afirst housing 61 in which the fan motor 60 is accommodated, and a secondhousing 62 in which the first housing 61 is accommodated. The secondhousing 62 may open from above to form an opening 620, and the firsthousing 61 may be inserted into the inside of the second housing 62through the opening 620. At a top of the second housing 62, a cover 63may be provided to cover the opening 620.

The fan motor 60 may provide a stronger suction force than fan motors oftypical robot cleaners. Therefore, the fan motor 60 may improve cleaningefficiency of the robot cleaner 1. According to some embodiments, thefan motor 60 may be a fan motor having a strong suction force, which isapplied to canister type cleaners or upright type cleaners.

The shape of the first housing 61 may correspond to that of the fanmotor 60. When the fan motor 60 is substantially in the shape of acylinder, the first housing 61 may also be substantially in the shape ofa cylinder.

In a side of the first housing 61, an inlet opening 611 through whichair inhaled by a suction force of the fan motor 60 enters the inside ofthe first housing 61 may be formed. The inlet opening 611 may be formedin a bottom of the first housing 61.

Also, in the first housing 61, an outlet opening 615 may be formed todischarge air entered the inside of the first housing 61. The outletopening 615 may be formed in an upper side portion of the first housing61. Air entered through the inlet opening 611 formed in the bottom ofthe first housing 61 may pass through the fan motor 60, and then bedischarged through the outlet opening 615 formed in the upper portion ofthe first housing 61. A single outlet opening 615 or a plurality ofoutlet openings 615 may be formed.

On an outer surface of the first housing 61, one or more chambers(hereinafter, also referred to as a first chamber 612 a and a secondchamber 612 b) may be provided to reduce a noise that may be generatedby air discharged through the outlet opening 615. The chambers 612 a and612 b may be positioned below the outlet opening 615.

Hereinafter, an embodiment in which two chambers 612 a and 612 b aredisposed for one outlet opening 615 will be described.

The chambers 612 a and 612 b may be positioned below the outlet opening615 to left and right sides of the outlet opening 615 with the outletopening 615 in between. More specifically, the first chamber 612 a andthe second chamber 612 b may be spaced from each other at the left andright sides of the outlet opening 615 with the outlet opening 615 inbetween. Air discharged through the outlet opening 615 may flow along aspace 616 between the first chamber 612 a and the second chamber 612 b.

When a single outlet opening 615 is provided, two chambers may be, asdescribed above, spaced from each other to form a flow path throughwhich air discharged from the outlet opening 615 passes. When aplurality of outlet openings 615 are provided, the same number ofchambers as that of the outlet openings 615 may be provided in such away to be spaced from each other, thus forming the same number of flowpaths as that of the outlet openings 615.

Meanwhile, the plurality of chambers may have the same size and shape ordifferent sizes and shapes.

Also, the number of the outlet opening 615 may not correspond to thenumber of the flow path through which air discharged through the outletopening 615 passes. Air discharged through the outlet opening 615 maycircle to move along the flow path formed by the two adjacent chambers612 a and 612 b.

Hereinafter, the two adjacent chambers 612 a and 612 b will bedescribed.

On a lateral surface 610 of the first housing 61, a plurality of ribs613 may protrude in the shape of the chambers 612 a and 612 b. When thefirst housing 61 is accommodated in the second housing 62, the chambers612 a and 612 b may be formed by the outer surface of the first housing61, an inner surface of the second housing 62, and the ribs 613. Theribs 613 may protrude in the shape of a closed curve from the outersurface of the first housing 61.

In the ribs 613, a plurality of slits 614 may be formed. The pluralityof slits 614 may be formed in the ribs 613 to correspond to both sidesof the flow path through which air discharged from the outlet opening615 passes. That is, the plurality of slits 614 may be respectivelyformed in ribs 613 a and 613 b of the first and second chambers 612 aand 612 b forming the flow path through which air discharged from theoutlet opening 615 passes. The current embodiment relates to a case inwhich the plurality of slits 614 are formed in the ribs 613, however, aplurality of holes may be formed in the ribs 613. Also, the shape of theslits 614 is not limited to a rectangular shape as shown in FIG. 4, andthe slits 614 may be formed in various shapes.

The second housing 62 may have a shape substantially corresponding tothe first housing 61. When the first housing 61 is in the shape of acylinder, the second housing 62 may also be in the shape of a cylinderto correspond to the first housing 61. The second housing 62 may openfrom above to form the opening 620 in which the first housing 61 isaccommodated.

The second housing 62 may include an inner housing 621 forming a spacein which the first housing 61 is accommodated, and an outer housing 622disposed around the outer side of the inner housing 621. The outerhousing 622 may surround at least one part of the inner housing 621. Apredetermined space may be formed between the inner housing 621 and theouter housing 622.

For air discharged from the outlet opening 615 of the first housing 61to enter the space between the inner housing 621 and the outer housing622, an inlet hole 623 may be formed in a portion of the inner housing621. The inlet hole 623 may be formed in a bottom or a side portion ofthe inner housing 621. When the inlet hole 623 is formed in the sideportion of the inner housing 621, the inlet hole 623 may be formed in alower side portion of the inner housing 621, which is close to thebottom of the inner housing 621.

An outlet hole 624 may be formed in the outer housing 622 to dischargeair entered between the inner housing 621 and the outer housing 622through the inlet hole 623 to the outside. The outlet hole 624 may beformed in an upper side portion of the outer housing 622.

The outlet hole 624 formed in the outer housing 622 may be located tocorrespond to the outlet 31 formed in the upper case 3. The airdischarged to the outside of the second housing 62 through the outlethole 624 may be discharged to the outside of the robot cleaner 1 throughthe outlet 31 formed in the upper case 3.

The cover 63 may cover the opening 620 of the second housing 62 fromabove. In an edge of the cover 63, a coupling member installing portion630 may be formed with which a coupling member is coupled. In the secondhousing 62, a coupling portion 626 may be formed to correspond to thecoupling member installing portion 630. The cover 63 may be mounted onthe second housing 62 by the coupling member penetrating the couplingmember installing portion 630 and the coupling portion 626. However, thecover 63 may be mounted on the second housing 62 in another manner.

FIG. 5 shows flow of air in a fan motor unit according to an embodiment.

Referring to FIG. 5, in a fan motor unit 6 according to an embodiment,air inhaled by the fan motor 60 may enter the inside of the fan motorunit 6 through the inlet opening 611 formed in the first housing 61, andbe discharged to the outside of the fan motor unit 6 through the outlethole 624 formed in the second housing 62.

Air entered the inside of the first housing 61 through the inlet opening611 may pass through the fan motor 60, and then be discharged throughthe outlet opening 615 formed in the first housing 61. The airdischarged through the outlet opening 615 may enter the space betweenthe inner housing 621 and the outer housing 622 through the inlet hole623 formed in the inner housing 621 of the second housing 62. The airentered toward the second housing 62 may be discharged to the outsidethrough the outlet hole 624 formed in the outer housing 622.

The air discharged to the outside of the fan motor unit 6 through theoutlet hole 624 may be discharged to the outside of the robot cleaner 1through the outlet 31 formed in the upper case 3.

FIG. 6 shows a part of a discharge flow path of a fan motor unitaccording to an embodiment.

Referring to FIG. 6, air discharged from the fan motor unit 6 accordingto an embodiment through the outlet opening 615 of the first housing 61may pass through the flow path 616 which is the space formed between theadjacent chambers 612 a and 612 b. In the rib 613 a of the first chamber612 a adjacent to the second chamber 612 b and the rib 613 b of thesecond chamber 612 b adjacent to the first chamber 612 a, a plurality ofslits 614 a and 614 b may be formed respectively. That is, the pluralityof slits 614 a and 614 b may be formed in edges of the flow path 616through which air discharged through the outlet opening 615 passes.

The air discharged through the outlet opening 615 may enter toward thesecond housing 62 via the flow path 616. Most of the air may passthrough the flow path 616, instead of entering the inside of thechambers 612 a and 612 b through the slits 614 a and 614 b.

The chambers 612 a and 612 b may function to reduce a noise that may begenerated by air passing through the flow path 616. The chambers 612 aand 612 b may cause a frequency of air passing through the flow path 616to produce resonance. That is, the chambers 612 a and 612 b may cause afrequency of air entered through the plurality of slits 614 a and 614 bto produce resonance. Thereby, the chambers 612 a and 612 b may reduce anoise that may be generated by inhaled air.

The chambers 612 a and 612 b may reduce a noise of a specific frequencyregion depending on the volume and shape. The volume and shape of thechambers 612 a and 612 b may be appropriately adjusted to reduce a noiseof a specific frequency region according to an environment, such as thekind of the fan motor 60, the sizes and shapes of the housings 61 and 62or the cases 2 and 3, etc., in which the robot cleaner 1 is used.

Hereinafter, components of a first housing according to anotherembodiment will be assigned the same reference numerals as thoseassigned to the corresponding ones of the first housing described abovewith reference to FIGS. 3 to 6. Also, in the following description, thechambers included in the first housing mean chambers located between thefirst housing 61 and the second housing 62, like the chambers 612 a and612 b described above with reference to FIGS. 3 to 6.

FIGS. 7 and 8 show first housings according to other embodiments.

Referring to FIG. 7, a first housing 61 a according to anotherembodiment may include the chambers 612 a and 612 b formed to the leftand right sides of the outlet opening 615 below the outlet opening 615.The chambers 612 a and 612 b may be formed by the ribs 613 a and 613 b.In the ribs 613 a and 613 b, a plurality of slits 614 c and 614 d may beformed.

Unlike the slits 614 a and 614 b shown in FIGS. 3 to 6, the slits 614 cand 614 d may be formed in portions of the ribs 613 a and 613 b, whichare opposite to each other in a vertical direction. That is, the slits614 c and 614 d may be formed in other locations, not in the edges ofthe flow path 616 through which air discharged through the outletopening 615 flows.

However, locations at which the slits 614 c and 614 d are formed are notlimited to these locations, and the slits 614 c and 614 d may be formedin appropriate locations for efficiently reducing a noise of the robotcleaner 1. For example, slits may be formed in at least one of ribs thatare vertically opposite to each other or in at least one of ribs thatare horizontally opposite to each other.

Referring to FIG. 8, in the chambers 612 a and 612 b included in thefirst housing 61 b, a plurality of holes 619 a and 619 b may be formed,instead of a plurality of slits. The plurality of holes 619 a and 619 bmay be formed at both adjacent ribs 613 and 613 b in the two adjacentchambers 612 a and 612 b. Also, when the plurality of holes 619 a and619 b are formed in the ribs 613 a and 613 b, a noise generated byinhaled air may be reduced due to resonance by the chambers 612 a and612 b without interfering with flow of air, like the embodiment in whichthe plurality of slits 614 a and 614 b are formed in the ribs 613 a and613 b.

Also, the shape of the chambers 612 a and 612 b is not limited to therectangular shape shown in FIGS. 3 to 8. Accordingly, locations in whichslits or holes are formed may also be appropriately selected accordingto a shape of chambers or an environment of a fan motor unit.

FIG. 9 shows a first housing according to another embodiment.

Referring to FIG. 9, a first housing 61 c according to anotherembodiment may include one or more chambers 612 a and 612 b.Hereinafter, the chamber 612 a located to the left of the outlet opening615 will be described. When a plurality of chambers are included in thefirst housing 61 c, the following content about the chamber 612 a willbe applied in the similar manner to the other chambers.

The chamber 612 a may include one or more partition walls 617 a and 617b. An inside space of the chamber 612 a may be partitioned by thepartition walls 617 a and 617 b.

By partitioning the space of the chamber 612 a by the partition walls617 a and 617 b to change the volume and shape of the chamber 612 a, afrequency region causing resonance may vary. Resonance produced by thechamber 612 a may reduce a noise generated by air discharged through theoutlet opening 615. Since the chamber 612 a is partitioned by thepartition walls 617 a and 617 b, a noise of a specific frequency regionmay be reduced.

The partition walls 617 a and 617 b may extend vertically in the insideof the chamber 612 a, as shown in FIG. 9. A plurality of partition walls617 a and 617 b may be positioned in the inside of the chamber 612 a, asnecessary, and also, the partition walls 617 a and 617 b may have a bentshape. Also, spaces 6120 and 6121 partitioned by the partition walls 617a and 617 b may have the same volume or different volumes.

The remaining components except for the partition walls 617 a and 617 bmay be the same as or similar to the corresponding ones included in thefirst housing described above with reference to FIGS. 3 to 8.

FIG. 10 shows a first housing according to another embodiment.

Referring to FIG. 10, a first housing 61 d may include one or morechambers 612 a and 612 b, like the first housing 61 c shown in FIG. 9.Hereinafter, a chamber 612 a located to the left of the outlet opening615 will be described. When a plurality of chambers are included in thefirst housing 61 c, the following content about the chamber 612 a willbe applied in the similar manner to the other chambers.

In the chamber 612, one or more partition walls 617 c and 617 d may beincluded. The partition walls 617 c and 617 d may extend horizontally inthe inside of the chamber 612 a. The partition walls 617 c and 617 d maypartition the inside space of the chamber 612 a to change the volume andshape of the chamber 612 a, like the partition walls 617 a and 617 bshown in FIG. 9. Spaces 6122 and 6123 partitioned by the partition walls617 c and 617 d may have the same volume or different volumes. Thechamber 612 a including the partition walls 617 c and 617 d may reduce anoise of a specific frequency region caused by air discharged throughthe outlet opening 615.

The remaining components except for the partition walls 617 c and 617 dmay be the same as or similar to the corresponding ones included in thefirst housing described above with reference to FIGS. 3 to 8.

The direction in which the partition walls 617 a and 617 b or 617 c and617 d extend is not limited to the embodiments shown in FIGS. 9 and 10.A plurality of partition walls may be included in one chamber, asnecessary, and also, the partition walls may have a bent shape. Also, aninside space of each chamber partitioned by the partition walls may havethe same volume or different volumes.

When a plurality of chambers are provided, inside spaces of theplurality of chambers may be partitioned to different shapes,respectively, by a plurality of partition walls to cause resonance withrespect to different frequency regions.

As such, the volume of each chamber may be adjusted by at least onepartition wall to reduce a noise of a specific frequency region.

FIG. 11 shows a state in which sound-absorbing materials are installedin chambers according to another embodiment.

Referring to FIG. 11, one or more sound-absorbing materials 618 may bepositioned in the chambers 612 a and 612 b provided in a first housing61 e according to another embodiment. The sound-absorbing materials 618may be made of a substance that absorbs energy of sound, and may includewool, a sponge, or a porous fiber material such as a glass fiber. Insome embodiments, a plate material, such as plywood or a hardfiberboard, may be used.

By positioning the sound-absorbing materials 618 in the chambers 612 aand 612 b, a noise that may be generated in the fan motor unit 6 may bemore efficiently reduced.

When a plurality of chambers are included in the first housing 61 e, thesound-absorbing materials 618 may be located in the respective chambersor in some of the chambers. Also, when the chambers are partitioned bypartition walls to form partitioned spaces, the sound-absorbingmaterials 618 may be located in the respective partitioned spaces or insome of the partitioned spaces.

FIG. 12 is a perspective view of a robot cleaner according to anotherembodiment, and FIG. 13 shows a state in which air flows in a fan motorunit according to another embodiment.

Referring to FIGS. 12 and 13, a robot cleaner 7 according to anotherembodiment may be different from the robot cleaner 1 shown in FIGS. 1 to11 in that a fan motor unit 8 is positioned horizontally in the insideof the robot cleaner 7. In the robot cleaner 1 shown in FIGS. 1 to 11,the fan motor unit 6 may be positioned vertically.

The above description about the brush unit 5, the wheels 4, the lowercase 2, and the upper case 3 shown in FIGS. 1 to 11 may be applied inthe similar manner to a brush unit 92, wheels 93, a lower case 90, andan upper case 91 except for the fan motor unit 8 positionedhorizontally.

In the robot cleaner 1 shown in FIGS. 1 to 11, the fan motor unit 6 maybe positioned vertically so that air inhaled through the inlet 21 entersthe fan motor unit 6 through the inlet opening 611 formed in the bottomof the fan motor unit 6. The air entered the fan motor unit 6 may passthrough the fan motor 60 and then be discharged through the outletopening 615 located in the upper portion of the first housing 61. Theair discharged through the outlet opening 615 may pass through the spacebetween the first housing 61 and the second housing 62 and then bedischarged to the outside of the fan motor unit 6 through the outlethole 624 formed in the upper portion of the second housing 62.

As such, in the robot cleaner 1 shown in FIGS. 1 to 11, inhaled air maymove in the vertical direction.

However, in the robot cleaner 7 according to another embodiment as shownin FIGS. 12 and 13, the fan motor unit 8 may be positioned horizontallyso that air inhaled through an inlet 900 may move horizontally. Also,the above description about the robot cleaner 1 shown in FIGS. 1 to 11may be applied in the similar manner to the robot cleaner 7 shown inFIGS. 12 and 13, except that air moves horizontally.

A fan motor 80 may be accommodated in a first housing 81, and the firsthousing 81 may be accommodated in a second housing 82. The first housing81 may include one or more chambers 812 a and 812 b in which a pluralityof slits are formed, to reduce a noise that is generated by flow of air.The chambers 812 a and 812 b may be formed by one or more ribs 813 a and813 b protruding from an outer side surface of the first housing 81.Inside spaces of the chambers 812 a and 812 b may be partitioned by oneor more partition walls. Also, one or more sound-absorbing materials maybe installed in the chambers 812 a and 812 b.

Air entered the fan motor unit 8 may pass through the fan motor 80 andthen be discharged to the space between the first housing 81 and thesecond housing 82 through an outlet opening 810 formed in the firsthousing 81. The air entered the space between the first housing 81 andthe second housing 82 may be discharged to the outside of the fan motorunit 8 through an outlet hole 820 formed in the second housing 82. Theair discharged to the outside of the fan motor unit 8 may be dischargedto the outside of the robot cleaner 7 through an outlet 910 formed inthe upper case 91.

As described above, by forming chambers in a housing of a fan motorunit, and forming a plurality of slits in ribs forming the chambers, itmay be possible to reduce a noise that may be generated by flow of air.Also, the chambers in which the plurality of slits provided to reduce anoise are formed may be positioned in the edges of a flow path so as notto interfere with flow of air, thereby preventing a suction force of afan motor from being lost.

By the configuration, it may be possible to reduce a noise caused byflow of air without any loss in suction force of the fan motor. Also, bychanging the volume and shape of the chambers, a noise of a specificfrequency region may be reduced.

The above description about the configuration of the chambers in whichthe plurality of slits are formed to reduce a noise may also be appliedin the similar manner to stick type cleaners, canister type cleaners,and the like, as well as robot cleaners.

The invention claimed is:
 1. A robot cleaner comprising: a fan motorconfigured to generate a suction force; a first housing in which the fanmotor is accommodated; a second housing in which the first housing isaccommodated; and a chamber positioned between the first housing and thesecond housing, wherein a plurality of slits are formed in the chamber.2. The robot cleaner of claim 1, wherein in a side of the first housing,an inlet opening through which air passed through the fan motor entersthe inside of the first housing is formed, and in another side of thefirst housing, an outlet opening through which the air entered theinside of the first housing is discharged is formed.
 3. The robotcleaner of claim 2, wherein in a side of the second housing, an outlethole is formed, and air entered between the first housing and the secondhousing through the outlet opening formed in the first housing isdischarged through the outlet hole formed in the second housing.
 4. Therobot cleaner of claim 3, wherein at least two of the chambers areprovided, and the air entered between the first housing and the secondhousing passes between chambers adjacent to each other among the atleast two chambers.
 5. The robot cleaner of claim 4, wherein theplurality of slits formed in the chamber are formed in one surface ofthe chamber opposite to one surface of a chamber adjacent to thechamber.
 6. The robot cleaner of claim 2, wherein a plurality of thechambers are provided to left and right sides of the outlet openingformed in the first housing.
 7. The robot cleaner of claim 1, whereinthe chamber is formed by an outer side surface of the first housing, arib protruding from the outer side surface of the first housing, and aninner side surface of the second housing.
 8. The robot cleaner of claim1, wherein the chamber includes a partition wall partitioning an insidespace of the chamber.
 9. The robot cleaner of claim 1, wherein asound-absorbing material is installed in an inside space of the chamber.10. The robot cleaner of claim 1, wherein when a plurality of thechambers are provided, a sound-absorbing material is installed in atleast one chamber of the plurality of chambers.
 11. The robot cleaner ofclaim 1, wherein an inside space of the chamber is partitioned to aplurality of spaces by a partition wall, and a sound-absorbing materialis installed in at least one space of the plurality of spaces.
 12. Therobot cleaner of claim 1, wherein an inlet opening is formed in a lowerportion of the first housing, and an outlet opening is formed in anupper portion of the first housing.
 13. The robot cleaner of claim 12,wherein two chambers are positioned below the outlet opening in such away to be spaced from each other, and air discharged through the outletopening passes between the two chambers.
 14. The robot cleaner of claim1, wherein the second housing includes an inner housing in which thefirst housing is accommodated, and an outer housing surrounding at leastone portion of the inner housing.
 15. The robot cleaner of claim 1,wherein the chamber is positioned between the first housing and theinner housing.